Field of the Invention
The present invention relates to developing apparatuses and process cartridges included in electrophotographic image forming apparatuses, and electrophotographic image forming apparatuses.
Description of the Related Art
Widely known electrophotographic image forming apparatuses include developing apparatuses each including a developer carrying roller and a developer regulating member. The developer regulating member abuts on the developer carrying roller in a developer layer thickness regulating part to form a thin layer of a developer, and perform frictional charge (tribomatic charging) on the developer.
Japanese Patent Application Laid-Open No. 2006-251730 discloses a developer regulating member for controlling the amount of charges of a developer layer to be uniform, wherein a developer intake portion is disposed in a portion upstream of an abutting part with a developer carrying roller in the developer traveling direction to circulate a developer between the surface of the developer carrying roller and the developer intake portion. This developer regulating member facilitates the circulation of the developer between the surface of the developer carrying roller and the developer intake portion, and is effective in providing a uniform amount of charges. Unfortunately, the developer on the developer carrying roller is unlikely to be developed in regions having low image density, particularly in a region of a solid white image. Such a developer will repeatedly receive friction between the developer regulating member and the developer feed roller to increase the amount of charges of the developer. In contrast, the developer on the developer carrying roller is mostly developed in regions having high image density, particularly in a region of a solid black image. This phenomenon increases the difference in the amount of charges of the developer between the region of a solid white image and the region of a solid black image, thus generating ghost images.